1. Technical Field
The invention relates to a method for measuring a rotation angle, in which at least one optical grating radial with respect to the rotation axis is pivoted relative to one or more slits parallel thereto, as well as to a rotation angle measuring device having at least one pivotable, radial, optical grating, through whose center passes a rotation axis, whose angular position is to be measured and with one or more slits positioned upstream of the optical grating.
2. Description of Prior Art
Optical rotation angle measuring devices of the aforementioned type are known per se. They have radial, optical gratings pivotable about the center thereof and one or more slits positioned upstream of the same. The known rotation angle measuring devices make high demands. Thus, they are sensitive to environmental influences, expensive and not suitable for mass use. Due to the diffraction effects, their resolution is also greatly limited, because these effects are noticed in the range of a few .mu.m in the case of line structures. Very high demands are also made on the axial setting precision and the other geometrical parameters. Such rotation angle measuring devices are required for measuring the accelerator position in vehicles equipped with a catalyst in order to optimize the action thereof. Thus, angular precisions of a few hundredths of a degree are required. Obviously in such cases an inexpensive mass product is needed, but this must be as insensitive as possible to external disturbing influences.